It has been known that in order to prevent the recording head of an ink jet recording apparatus from becoming plugged, or to prevent the similar problems, an ink jet recording apparatus is equipped with a unit for suctioning ink from the recording head to restore the recording head in performance. As an ink cartridge which comprises a waste ink containing portion for storing the waste ink, that is, the ink suctioned away from the suction type performance recovery unit, and is replaceably mountable in an ink jet recording apparatus, there have been known a few ink cartridges structured like the one disclosed in Japanese Laid-open Patent Applications 6-340092 and 5-4349. In the case of these ink cartridges, the waste ink inlet of the waste ink containing portion is generally provided as a part of the front wall of the waste ink containing portion, in terms of the direction in which an ink cartridge is inserted into a recording apparatus. Thus, an ink jet recording apparatus which employs such an ink cartridge needs to be provided with an ink discharge tube through which waste ink can be drawn out of the main assembly of the recording apparatus, and the waste ink discharge tube needs to be located in the front portion of the recording apparatus, in terms of the ink cartridge insertion direction.
However, the above described structural arrangement is problematic for the following reason. That is, in order to make a portable printer thinner, an ink container therefor must also be made to be thinner. Thus, if the waste ink container of an ink container is structured as described above, the objective of increasing an ink container in capacity to reduce it in replacement frequency contradicts the objective of reducing a portable printer in size and thickness; in other words, it is very difficult to accomplish both objectives (first technical problem).
Further, if the waste ink holding portion itself is made as small as possible in size, it becomes difficult for the waste ink to disperse satisfactorily and quickly in the waste ink holding portion after being absorbed into the waste ink holding portion. This creates the condition that the waste ink is nonuniformly distributed in the waste ink holding portion, that is, certain areas of the waste ink holding portion become excessively saturated with the waste ink. When the waste ink holding portion is in this condition, it is possible for the waste ink therein to leak into, and/or out of, the apparatus, due to the vibrations to which the apparatus is subjected while the apparatus is carried, impacts to which the apparatus is subjected as the apparatus is dropped, and/or changes in temperature (second technical problem).
There is another problem. That is, as ink jet recording has come close in quality to silver-salt photography, ink jet recording apparatuses enabled by software technologies to record an image in a manner of covering the entire surface of a recording medium, that is, ink jet recording apparatuses capable of producing prints with no border, or margin (which hereinafter may be referred to as borderless prints), have come to be marketed. In these ink jet recording apparatuses, a single or plurality of ink absorbing members for absorbing ink are placed on a platen, across the areas where the ink droplets ejected toward slightly outside the edges of the printing paper land when the ink jet recording apparatus is in the borderless mode, so that the ink droplets ejected toward slightly outside the recording paper range are caught, absorbed, and retained by the ink absorbing members to make it possible for an image to be formed on the following recording paper without soiling the recording paper.
In the case of the above arrangement, however, the ink absorbing members are held by the platen. Therefore, in order to increase the ink absorbing members in capacity, the printer itself has to be increased in size, which is a problem. This problem is more serious in the case of a portable printer, for the following reason. That is, since a portable printer is frequently carried, it must be greater than a stationary printer, in the margin of reliability in terms of leakage. Further, the capacity of the waste ink absorbing members must be set according to not only the entire amount of ink which will be used during the duration of the service life of the main assembly of an ink jet printer, but also, the frequency of usage by a heavy user. Thus, unless an innovative approach is made, it is difficult to substantially reduce the size of an ink jet printer (third technical problem).